Considers hydraulic problems (from surge), air-related problems (both vacuum and air-release), and mechanical problems (from slam) that can be addressed with valves. A technical presentation, but light on math and heavy on metaphorical examples that make the hard-to-see inner workings of a fluid system easy to visualize and understand.

1. HOW TO USE VALVES TO
PROTECT FORCE MAINS
Brian Gongol
DJ Gongol & Associates, Inc.
January 28, 2015
Nebraska Snowball Conference

2. Let's start with a beer keg

3. If you pump a few times, you add pressure

4. Pumping too much creates foamy beer

5. Beer is relatively incompressible

6. Releasing a little volume eases lots of pressure

7. Water in a pressurized system: Same behavior

8. Not zero like a solid (steel or concrete)

9. But close

10. Squirt guns and belly flops prove it

11. Water is not like air in a storm door cushion

12. But also unlike pushing on a pool cue

13. Energy is transmitted quickly but not instantly

14. Energy is conducted as a wave

15. Surge is like a train starting or stopping

16. Energy transmits through couplers

17. Slam is the train sliding back downhill

18. Blood pressure is a surge event

19. Everyone with a dishwasher knows surge

20. Driving while hauling tank of liquid

21. Don't jam on gas or brake

22. Operate smoothly

23. Sudden starts/stops could drop a transmission

24. Momentum/inertia matters

25. Centrifugal pump from stop to 100%

26. Like hitting gas pedal to floor

27. Shock demand is hard on transmission

28. Rotative speed isn't 100% instantaneously

29. Pipe friction

30. Fire hose/garden hose/flexible hose

31. PVC pipe

32. Ductile iron, copper, and other metal pipe

33. More friction means more surge dissipation

34. But also more headloss and energy use

35. High efficiency trade-off with surge potential

36. Magic number: 10 critical periods

37. Cross-cancellation of wave action

38. Surge moves at the speed of sound in water...

39. ...modified by pipe characteristics

40. Published tables of surge wave speed ("a")

41. "a" for plastic pipe is 900 fps (615 mph)

42. "a" for ductile iron is 5,000 fps (3400 mph)

43. Plastic expands and absorbs the wave energy

44. Metal disspates less wave energy

45. Surge mitigation techniques

46. VFDs might help
But what part of the scale
is actually effective on surge?

47. Depends upon static head

48. Soft starters might help
 But what about pump shutdown?

49. What about power failure?

50. Automatic pressure-control valves

51. Air is also a problem

52. Air release upon pipeline fill

53. Dynamic operation to release air

54. Vacuum-breaking upon pressure drop

55. Air in solution in water: About 2%

56. Air valves

57. Air restricts pipe diameter

58. Can be significant

59. Air pockets will build

60. Imagine trapping a tough balloon in the pipe

61. Lots of compression possible...

62. ...but dangerous high pressure results

63. Weight of a column of water
 4" diameter, 500' long
 43.55 cubic feet
 325.75 gallons

64. At 8.3 lbs per gallon: 2700 lbs. (a Honda Civic)

65. You have to break that vacuum

66. Pipe is not like a drinking straw
 Something has to give eventually

67. How it's harmful

68. Long-term wear on pipes

69. Main breaks

70. Valve failures

71. Backspinning pumps

72. Pipe swings inside plant

73. Leaks

74. Contamination by negative-pressure events

75. We've covered hydraulic problems (air/water)

76. Upsurge and downsurge are hydraulic

77. Slam is mechanical

78. Slam comes from column reversal

79. Slam and surge are independent

80. Check valves are used for protection

81. Prevent simple column reversal

82. Ball check valves

83. Weighted-flapper check valves

84. Cushioned check valves

85. Non-slam check valves

86. Close fast enough to prevent slam

87. Don't close too fast for pumps and systems

88. Quick self-closure isn't actual slam

89. Slam is involuntary seating of the valve

90. Some valves can control both surge and slam
 Checktronic
 Overcoming high head after bringing pump up to speed

91. Illustrations

92. Tank to closed valve

93. Pump to closed valve

94. Demo: Surge valve

95. Demo: Sewage air-release valve

96. Demo: Water air-release valve

97. Demo: Wide-body air-release valve

98. To recap
 Pipes, valves, and equipment are endangered by three
problems:
 Hydraulic upsurge and downsurge
 Hydraulic consequences of air
 Mechanical slam
 These problems can be resolved through multiple means
 Automatic valves are often the best choice

99. You don't have to figure it out alone
 Free surge analysis available
 Call: 515-223-4144
 Email: info@djgongol.com

100. Questions?
 Thank you for coming!

101. Thank you for your attention!
 Contact us anytime with
questions
 Brian Gongol
 DJ Gongol & Associates
 515-223-4144
 info@djgongol.com

102. References
 Catalog photos of valves are courtesy GA Industries
 All other photos are original work by Brian Gongol. All rights
reserved.